Trying to set SLICEM LUT DI1 inputs
These exist for LUTA, LUTB, and LUTC only
Can either be an external signal, another LUT's data input, or another LUT's carry
Note: mux input pattern is irregular

Result:
Neither external input nor carry input set any unknown bits
Unclear what is going on
Maybe an earlier test incorrectly set these?
Additionally, I could not get BDI1 to activate
Maybe should do a closer pass on BI/DI, which may be easier to trigger

